Method for forecasting the remaining operating life of a product in the case of cyclic loading

摘要

Method for forecasting the remaining operating life of a product in the case of cyclic loading, wherein applying to the surface of a comparison pattern two piezoelectric transducers in a fixed distance from each other, the superficial ultrasonic waves through the first piezoelectric transducers and excited by the second piezoelectric transducers are received, the transit time t_e of the ultrasonic signals between the piezoelectric transducers is measured, the two piezoelectric transducers to the surface of the item to be attached, and the transit time t of the ultrasonic signals between the piezoelectric transducers is measured, the two piezoelectric transducers on the surface of the product in the range with the most defective can be provided. the maximum propagation time t_{a maximum} is reached, a cyclic loading of the product with a constant strain amplitude is carried out, flat pattern of the material of the product to strength, and on the surface of each pattern in the most stressed area of two piezoelectric transducers are mounted in a fixed distance from one another, and the running times of the ultrasonic signals between the piezoelectric transducers are measured, characterized in that the transit time t₁ of the ultrasonic signals between the piezoelectric transducers according to the reaching of a cycle δn of the product is measured, the test for fatigue on at least three flat samples from the material of the product is carried out, the transit time t of the ultrasonic signals between the two piezoelectric transducers of the pattern is measured, wherein a transit time t₀in front of a load and the propagation times t₁, t₂, t₃, .., t_nafter n₁, N₂, N₃, .., N_n Load cycles are to be measured, wherein the pattern in the measurement of the transit times are not loaded, wherein the load in the case of high constant strain amplitude, which takes place to the destruction of the pattern ..